﻿#region BSD 3-Clause License
/* Copyright (c) 2012, Intel Corporation
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *    
 * 3. Neither the name of Intel Corporation nor the names of its contributors may
 *    be used to endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
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 */
#endregion

using System;

namespace OpenHopla.Geometry
{
    public class TriangleTester : PolygonTester
    {
        public bool IsIsosceles(Triangle triangle)
        {
            return DistinctSegmentLengths(triangle).Count == 2;
        }

        public bool IsScalene(Triangle triangle)
        {
            return DistinctSegmentLengths(triangle).Count == 3;
        }

        public bool IsRight(Triangle triangle)
        {
            // How low can you go?
            double epsilon = 0.00000000000001;

            double a = triangle.SegmentLengths[0];
            double b = triangle.SegmentLengths[1];
            double c = triangle.SegmentLengths[2];

            return (Calculator.Equals(a * a + b * b, c * c, epsilon) ||
                    Calculator.Equals(a * a + c * c, b * b, epsilon) ||
                    Calculator.Equals(b * b + c * c, a * a, epsilon) );
        }
    }
}
